lawson



Feb. 28, 1956 R. H. LAWSON 2,736,178

SPEED CHANGING MECHANISM FOR KNITTING MACHINES Filed Nov. 17, 1954 6 Sheets-Sheet 1 E/II mlm mum l l INVENTOR. FlG. l. ROBERT H. LAWSON 1' BY mqihm,

ATTORNEYS Feb. 28, 1956 R. H. LAWSON SPEED CHANGING MECHANISM FOR KNITTING MACHINES s Sheets- Sheet 2 Filed Nov. 17, 1954 m S N wE iwmwiiilwliiliw mm x m s 1 m mm on W AWH "H 4 7 III I L w A ow 3 m P N I H W V VA??? m v m J ERI m E .l H I ll |l|| Hm .I B F .l. .8 8 I ll 1? WM W 8 A 8 5 8 Lfi m m mm -l l. l H -l. I H Hmm h t. -tflwb .l. IIONHIWI .FF mm mm mm W 3 a n Q vw /|l|||ll|l|l.|l|||l|||l||ll|\\\ Feb. 28, 1956 R. H. LAWSON 2,736,178

SPEED CHANGING MECHANISM FOR KNITTING MACHINES 6 Sheets-Sheet 3 Filed Nov. 17, 1954 INVENTOR.

ROBERT H. LAWSON 4, it) Z6 ATTORNEYS Feb. 28, 1956 R. H. LAWSON SPEED CHANGING MECHANISM FOR KNITTING MACHINES 6 Sheets-Sheet 4 Filed Nov. 1'7, 1954 INVENTOR. BROBERT H; LAWSON [31.44 3 1 ATTORNEYS Feb. 28, 1956 R. H. LAWSON 2,736,178

SPEED CHANGING MECHANISM FOR KNITTING MACHINES Filed Nov. 17, 1954 6Sheets-Sheet 5 SI] l|ll|ll I Illlllll I i! F q, 8 I "a, 9 2 v I llllll H I I r III I]! lllll II] H [H] o g 0 '0 an 9 1| I[ a I 1| I O ion INVENTOR.

ROBERT H. LAWSON ATTORNEYS Feb. 28, 1956 R. H. LAWSON 2,

SPEED CHANGING MECHANISM FOR KNITTING MACHINES Filed NOV. 17, 1954 6 Sheets-Sheet 6 INVENTOR. t BBOBERT H. LAWSON ATTORNEYS United States Patent SPEED CHANGING MECHANISM FOR KNITTING MACHINES Robert H. Lawson, Laconia, N. H., assignor to Scott & Williams, Incorporated, Laconia, N. H., a corporation of Massachusetts Application November 17, 1954, Serial No. 469,529

7 Claims. (Cl. 66-56) minimize damage in the event that some accidental occurrence causes the knitting mechanism to stop operating. One of these pulleys is an idle pulley while the other two are low and high speed pulleys, respectively. Only two speeds of operation of the knitting machine are thus afforded and during operation the belt is automatically shifted between the low and high speed pulleys to secure proper speeds of operation, the low speed being used during changeovers of the mechanism and during certain phases of knitting while the high speed is used in straightaway knitting. The'fact that only two speeds are availableresults in lowered production. rate since either the high speed which is provided must be abnormally lowfor certain operations for which the machine could permissibly be operated at quite high speed, or the low speed must be used for operations which could be carried out at a higher speed but not at the high speed which would be permissible for other operations. For example, in knitting on a plain machine the welt, leg, foot and loopers rounds of a stocking a quite high speed of operation would be permissible. In the reciprocatory knitting of heels and toes a somewhat lower speed would be desirable. A still lower speed is desirable for main pattern drum moves controlling yarn changes, clutching,

etc. A still lower speed must be provided, however, for such drum moves as require close timing, such as are involved in make-up and transfer, as well as for the resulting machine operations.

In a double cylinder type of machine a quite high speed may be used during plain rib knitting, the formation of loopers rounds, etc. A lower speed is desirable for linkslinks operation. A still lower speed is desirable for heel and toe formation and further speed reduction may be necessary during drum moves and yarn changes.

In the present machines having only two speeds available it is evident that these various operations must be grouped with the necessity for using abnormally low unrequired speeds for some of them. Desirably, therefore, there is made provision for at least four speeds and, to avoid the use of multi-speed individual motors which are costly and involve rather elaborate electrical controls, there is provided in accordance with the invention speed change gearing interposed between a constant speed indi vidual motor or a constant speed line shaft and the usual pulleys, as above described, of the machine. Specifically,

; with the low and high speed pulley changes of the knitting machine, giving a possibility of six speed variations which are ample to satisfy all requirements, making it possible to have each phase of the knitting machine involve a speed which is near the maximum permissible for that phase. The change speed gearing is controlled by the pattern mechanism of the knitting machine to secure proper coordination of the speed and the phases of operation.

The broad object of the invention has to do with the satisfactory accomplishment of the ends above described. This object as well as subsidiary objects having particularly to do with details of construction and operation will become apparent from the following description read in conjunction with the accompanying drawings, in which:

Figure 1 is an elevation showing a knitting machine, in outline, associated with the speed change mechanism of the present invention, and showing in diagram the electrical control devices for effecting speed changes;

Figure 2 is a horizontal section through the speed change gear box, the section being taken on the plane indicated at 22 in Figure 3;

Figure 3 is a vertical section through the speed change gear box, the section being taken on the plane indicated at 3-3 in Figures 2 and 4;

Figure 4 is a plan view of the speed change gear box with the top cover broken away to show interior details;

Figure 5 is a plan view showing the top of the speed change gear box and, in particular, the electrically operated pneumatic valves and their connections for eifecting gear changes;

Figure 6 is a fragmentary side elevation of the machine showing a portion of the mechanism involved in speed control;

Figure 7 is a fragmentary perspective view showing additional mechanism involved in the speed control;

Figure 8 is a fragmentary perspective view showing cer tain switch control means; and

Figure 9 is a wiring diagram of the electrical control system.

The invention may be best described by considering first the details of the speed change gearing. This comprises a casing having a lower section 2 and an upper section 4 and adapted to contain lubricant for the mechanism. A shaft 6 is mounted in bearings 8 and 10 in the casing and has keyed to one end thereof a pulley 12 which, as later more particularly described, drives the belt 13 which runs on the three pulleys 15, 17 and 19 of the knitting machine M. .A pulley 14 is journalled on the opposite end of the shaft on bearings 16 and is arranged to be belt-driven at 21 by either an individual machine motor of constant speed type or a pulley on a line shaft.

Formed on the pulley 14 is a gear 18 which meshes with an idler gear 20 (Figure 3) which, in turn, meshes witha gear 22 keyed to shaft 24 which is mounted in bearings 26 and 28 in the casing. The gears 18 and 22 may have the same number of teeth. The idler 20 may be omitted if the pulley 14 is driven in an opposite direction, gears 18 and 22 then being chosen to be directly in mesh.

A gear 30 keyed to the shaft 24 meshes with a gear 32 which is held against a collar 33 by a retaining ring 35 so as to be rotatable on the shaft 6. The gear 32 is provided with clutch teeth 34 which are arranged for engagement by the teeth 36 of a clutch collar 38 which is provided with a groove 39 for shifting by means of a fork later described. The collar 38 is splined to the shaft 6 by means of a key 40. A gear 42 is keyed to the shaft 6 and held against endwise movement by retaining rings. This gear meshes with a gear 44 which is rotatable on the shaft 24 and is held in position against a collar 4-5, pinned to shaft 24, by means of aretaining. ring ifii. is provided with clutch teeth engageable by teeth 43 of a clutch collar all provided with a groove 51 for engage ment by a shifting fork. The clutch collar 56 is splined to the shaft 24 by means of'a key 52; Also splined to the shaft 24 by the same key is a clutch collar provided with a groove 55 for engagement by a shifting fork and with teeth 56 engageable with teeth 58 carried by a gear 60 which is rotatable on shaft 24, being held against a backing collar 62, pinned to the shaft, by means of retaining ring 63. The gear 69 meshes with a gear '64 which is held between collars 66 and 63 on the shaft 6. An overrunning clutch arrangement is provided between the gear 64 and-shaft 6 by one or more axial slots 7! in the bore'through the gear 64 engageable by dogs 72 located in slots 74 which are milled into an enlargement 75 of the shaft, the dogs being urged outwardly by springs 76. The arrangement is such that, viewing the assembly from the left-hand end of shaft 6, shaft 6 is free to rotate clockwise at an angular speed greater than that of gear 64, but will be driven clockwise by gear 64 if it is not otherwise driven.

The shifting of clutch collar 33 is effected through fork 78 which is pinned to a rod 89 slidablc in the frame and urged toward the right, as viewed in Figure 4, by aspring 82 bearing against a rib 84 in the casing section 4. The rod may be moved toward the left under the action of a rocker 86 which is pivoted in the head of a bolt member 88.

Clutch collar 50-is shifted by means of a fork 9%) which is secured to a rod 2 mounted to slide in the casing and urged toward the left, as viewed in Figure 4, by a spring 94, against the action of which it may be shifted toward the right by a rockerfidpivoted in the head of a bolt 98.

To aid spring 94 in overcoming resistance, the rod 92 may be urgedto the left by a rocker 97 pivoted in the head of a bolt 101.

The clutch collar.54 is shifted by a fork 99 secured to a rod 100, slidably mounted in the casing, and urged .toward the right, as .viewed in Figure 4, by a spring 102, against the action of which it may be moved toward the left by a rocker 104 pivoted in the head of a bolt 166.

The rockers 86, 96, 97 and 104 are arranged to be selectively rocked by pneumatically operated plungers under the control of electrically controlled valves. The rocker 86 is engageable by a plunger 168 mounted in a cylinder and arranged to be forced to the right, as viewed in Figure 5, by the introduction of air into the connection 112 froman electrically controlled valve 114.

The rocker 96 is arranged to be rocked by a similar plunger 116 mounted in an air cylinder 118 receiving air through connection IZO-from the electrically controlled valve 122.

The rocker 104 is arranged to be rocked by the plunger 124 in an air cylinder 126 receiving air through connection 128 from the electrically controlled valve 130.

The rocker 97 is arranged to be rocked by the plunger 127 in an air cylinder 129 receiving air through connection 131 from the electrically controlled valve 133.

Compressed air is provided to the valves 122,114, and 133 from a supply line 132. The valves are mounted on an electrical connection box 134 and are electrically controlled as hereafter described.

Before proceeding with the description of the controls for the valves 122, 114, 130 and 133, the operation of the gear box may be described for various combinations of open and closed positions of these valves.

Referring to the positions of the clutches as normal when they are positioned by the respective springs associated with their forks, it will be evident that the normal position of clutch 38 is closed, while the normal positions of clutches 50 and 54 are open. Accordingly, an open position of valve 114 produces disengagement of clutch 38. An open position of valve 122 producesengagement of clutch 50. An open condition of valve 133 aids spring 94 in producing an open condition of clutch 50. An open The. gear. 44..

condition of valve 130-produces-closedcondition ofclutch 54. With these preliminary considerations the eifects of various combinations of open and closed conditions of the valves may be outlined as follows:

Low speed of pulley 12 .is attained when valve 114 is open, valve 122 is closed and valve 130 is open. (Valve 133 may be either open or closed.) Under these'conditions, clutch 38 is disengaged, clutch 54 is engaged, and clutch 50 is disengaged. Thedrive from pulley. 14 is then through gears 18, 20 and22, shaft 24, clutch 54', gear. 60, gear 64, and shaft 6 through the overrunning clutch, the gear 64 driving the shaft. The reduction of speed between pulley 14and pulley 12 is determined by thereduction at gears 60 and 64.

Medium speed is provided with valves 114 and 122 both closed, with valve 130 either closed or open. Valve 133 is then desirably open though its action may be unnecessary unless spring 94.fails to act., The closedcondition of valve 114 provides engagement. of clutch' 38, whilcthe closed condition of valve 122 provides for, disengagement of clutch 50 by spring 94 aided by plunger 127. Under these conditions, the drive from pulley 14 is thrQughgears 18, 20. and 22, shaft 24, g ears 30 and 32, and clut ch.3.8 through. its spline to shaft 6. The medium speedisdetermined by the ratio of gear 30 to gear 32. As illustrated, this ratiois slightly. more than unity. Itwasgmentioned that the position of valve 130 for medium speedwasimmaterial. If the valve 130 is-closed, clutch 54 is. disengaged and, hence, there is, no drive through gear 60 and. gear 64. On the other hand, if valve 130, is open and clutch. 54 is accordingly engaged, there will be a drive fromv shaft 24 throughihis clutch, and gea1160. to gear 64. However, in view offthereduction.ratiobetween gears v60' and 64, the latter will .be rotated. ata speed. lower than that of ,shaft.61 and, accordingly, overrunning in the overrunning clutch will occur.

For highv speed operation,- valves 114and.122 are both open, and valve 133 is closed, the COIldltlOIlrOfVfllVC 130 being again immaterial. The, opencondition of valve 114 opens clutch v38. The open condition of..valve'122 closes clutch 50o Accordingly, the drive from pulley 14 is throughgears 18-, 20 and 22,;shaft 24, clutch 50, and gears 44- and;42 to shaft 6. A considerable speed step-up ratio is provided between gears 44 and .42, giving riseto high speed of rotation of pulley 12 relative to pulley 14. As before, the closed-or opencondition of clutch 54.is immaterial, there being no driveof-gear 64 .if this clutch is open, while in the case of lowspeed drive,:if the clutch is closed, the shaft 6 may overrun the gear 64 due to the presence of,the overrunningclutch.

Interruption of drive between pulley14 and ,pulley 12 may beaccomplished by providing an ,openconditiqn, of valve114 andclosed. conditionsof valves Y122 and 130. Under these conditions, all three clutchesaredisengaged andv there is no through drive. This-condition may be desirable for control by aknitting machinestoprnotion. As will be apparent, thismay be electrical in nature.

The other two possible combinations of conditions of the valves 114, 122and ISO-would involvev the valve 114 in closed condition and valve 122 in. open condition. These combinations must. be avoided since, as will be apparent, they would, involve jamming inthe gearbox. It may be noted:that.-these,conditionslwouldnot occur upon failure of 'theairsupply at 132,.whiehfailurewould merely lead to, the medium speedcondition,

While. the foregoing indicates that various, speed conditions may beattained in several diiferentways, a specific type of control. whichis desirable is herein illustratcd, and referencev may be first made to the wiring diagram of Figure 9. The solenoids which, when energizoiserve to open the respective valves 122, 114, 130 and 133 are indicated by the same numerals with. A appended. The electrical supply terminals :areindicated at 136, and associated with the solenoids .area main startingzswitch 138 and three double-pole double-throw switches 140,

eng ne 142 and,144. As indicated. by the diagram, the internal springs of these switches serve normally to urge them toward their lower pairs of contacts.

Referring to Figure 7, the start-stop switch 138 is indicated therein as arranged to be operated through the link 146 from the conventional belt shipping device 148 of the knitting machine, the switch being arranged to be opened when the belt is shifted to the idle pulley and closed when the belt is either on the low speed or high speed pulley. Associated with the link 146 is-also desirably a valve 150 which controls the air supply, to cut it oif when the belt is on the idle pulley.

The switch 144 is associated with the machine as illustrated in Figure 6. The actuating switch arm 152 is provided with a pin extending through a slot 154 in the lower end of a link 156 which is pivoted to a lever 158 pivoted to the machine frame at 160 and urged downwardly by a link 162 acted upon by a spring 164. The action of the spring 164 is stronger than the action of the internal spring of the switch 154 so that, as indicated in Figure 9, when the lever 158 is in its lower position the switch contact is made at the upper pair of contacts. The lever 158 is provided with a follower 166 arranged to be engaged by high lugs 168 on the main pattern chain 170. In the absence of a lug acting upon the follower 166 the switch 144 makes its upper contacts. When a high lug lifts the lever 158 contact is made at the lower contacts.

Figure 8 illustrates the mode of operation of the switches 140 and 142, the actuating arms of which are acted upon by respective cams 172 and 174 on the main cam drum 176 of the machine. In the absence of cams, each of the switches makes contact at its lower pair of contacts. The presence of a cam produces contact at the upper contacts of each.

As has been indicated above, the medium speed condition of the change speed mechanism is attained when the valves 114 and 122 are closed. For this condition, in the present arrangement, valve 130 is also closed. The medium speed condition is also independent of the condition of valve 133. Examination of Figure 9 will show that the medium speed condition therefore exists when no cam is acting upon either of switches 140 and 142. The purpose of the provision of switch 144 is to insure that following drive in high speed condition, if a transition to medium speed is to be made, there will be an attainment of this by a positive disengagement of clutch member 50. For this reason, whenever a transition to medium speed is to be accomplished, a high link is arranged to act upon the follower 166 to produce making of the lower contacts of switch 144. This energizes the solenoid 133A, opening valve 133, and providing pneumatic forcing of the shift bar 92 toward the left as viewed in Figure 3 in aid of the spring 94. This action is highly desirable since, under power drive, the friction between the engaging clutch elements may be sufficiently strong to prevent disengagement by the spring 94 alone. Once disengagement is effected, it is then no longer necessary to hold valve 133 open. Accordingly, a single high lug link will suffice to efiect the transformation to medium speed operation, and this lug may pass the follower, deenergizing the solenoid 133A, while, nevertheless, the medium speed condition will be continued. The links bearing the lugs 168 are, therefore, located in the chain only when medium speed is desired.

Low speed condition is attained when a cam 172 acts on the arm of switch 140. This produces closure of the upper contacts of that switch, and as will be evident from Figure 9, this results in energization of solenoids 114A and 130A. As has been pointed out, the opening of the valves 114 and 130 results in low speed condition.

High speed condition is attained when a cam 174 acts upon the operating arm of switch 142. This causes engagement of the upper contacts of this switch, and it will be noted that if, as would be normal, there is no lug beneath, the follower 166, so that switch 144 is making contact at its upper contacts, there will result energization of solenoids 114A and 122A with opening of the corresponding valves 114 and 122. The result,in accordance with the above discussion, is the high speed condition.

It will be noted from examination of Figure 9 that the electrical system prevents the existence of a condition in which valve 114 is closed and valve 122 is open. Thus, jamming in the gear box is prevented. 7

From the foregoing, it will be evident that there are provided in the driving system for the'knitting machine, and under the control thereof, three speed ratios, which, in combination with the high and low speed drive normally provided, will give six possible speeds. This range of speeds is ample to take care of all requirements and enables any particular phase of operation of the knitting machine to be carried out at an optimum speed without necessitating the compromises referred to in the beginning of this description. The overall speed of operation is, accordingly, greatly improved. It will be evident that the invention is applicable to all types of knitting machines, either circular or full-fashioned, and of the various types falling within these broad classifications. Any knitting machine is provided with either a main cam drum or its equivalent and also with a pattern chain or its equivalent. The speed changes are derived from these pattern mechanisms so as to be securable at the times of the various changes in phases of operation. Standard knitting machines, of course, involve automatic changes between their present high and low speeds, these being generally achieved by belt shifting. The total number of speed changes, six in the present instance, is controllable entirely from the knitting machine control elements.

It will be evident that various changes may be made in details of the invention without departing from its scope as defined in the following claims.

What is claimed is:

1. In a knitting machine having main speed change mechanism, pattern devices, and means operated by said pattern devices for controlling said main speed change mechanism, an auxiliary speed change mechanism in mechanical series with said main speed change mechanism, and means operated by said pattern devices for controlling said auxiliary speed change mechanism.

2. In a knitting machine having main speed change mechanism, pattern devices, and means operated by said pattern devices for controlling said main speed change mechanism, an auxiliary speed change mechanism in mechanical series with said main speed change mechanism, and means operated by said pattern devices for electrically controlling said auxiliary speed change mechanism.

3. In a knitting machine having main speed change mechanism, pattern devices, and means operated by said pattern devices for controlling said main speed change mechanism, an auxiliary speed change mechanism in mechanical series with said main speed change mechanism, and means operated by said pattern devices for pneumatically controlling said auxiliary speed change mechanism.

4. In a knitting machine having main speed change mechanism, pattern devices, and means operated by said pattern devices for controlling said main speed change mechanism, an auxiliary speed change mechanism in mechanical series with said main speed change mechanism, and means operated by said pattern devices for electropneumatically controlling said auxiliary speed change mechanism.

5. In a knitting machine having main speed change mechanism, pattern devices, and means operated by said pattern devices for controlling said main speed change mechanism, an auxiliary speed change mechanism of change gear type in mechanical series with said main speed change mechanism, and means operated by said pattern devices for controlling said auxiliary speed change mechanism.

6. In a knitting machine having pattern devices, a speed change mechanism arranged to drive the knitting mechanismof saidmachine including said pattern devices Refei'encessCitiedjn the fileof this patent 'andflarrangedjoybeV-drivenby mainfidrivingmeans, and

means, operated by said pattern devices for pneumatically UNITED"STATES' PATENTS contrlolling said speed change mechanism. 1;463 ,40 8 s n July 31,1923 71' In, a knitting machine having, pattern, devices, a 5 2,422,563 L -ki June 17, 1947 speed change mechanism arranged todrivc the knitting mechanism, of said machine including said pattern. de- FOREIGNEP'ATENTS- vices'and a-rrange to bedriven .by main -driving means, 525 644" GreatsBritain, Sept; 2, 1940 and, means operatedby said jpatterndevic'es for electro 419 GreatyBmain; Mar] 3 1954 pneumatically controlling said speedrchange mechanism. 10 i i w 

